[iwn] request for testing: iwn bluetooth coexistence config

[Adrian Chadd]

Hi,

This patch disables sending the btcoex messages to the 6200/6205 NICs. They
don't support bluetooth coexistence and people have reported that it causes
things to break.

http://people.freebsd.org/~adrian/ath/20130927-iwn-disable-btcoex.diff

Please test it out and let me know if it breaks things or fix things.



-adrian